chrX-71223830-G-C

Position:

• chrX-71223830-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000166.6(GJB1):​c.123G>C​(p.Glu41Asp) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E41K) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 22)
• Consequence: GJB1 NM_000166.6 missense
• Clinical Significance: Uncertain significance no assertion criteria provided U:1 O:1
• Conservation: PhyloP100: 4.22

Genes affected

GJB1 (HGNC:4283): (gap junction protein beta 1) This gene encodes a member of the gap junction protein family. The gap junction proteins are membrane-spanning proteins that assemble to form gap junction channels that facilitate the transfer of ions and small molecules between cells. According to sequence similarities at the nucleotide and amino acid levels, the gap junction proteins are divided into two categories, alpha and beta. Mutations in this gene cause X-linked Charcot-Marie-Tooth disease, an inherited peripheral neuropathy. Alternatively spliced transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain in NM_000166.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GJB1	NM_000166.6	c.123G>C	p.Glu41Asp	missense_variant	2/2	ENST00000361726.7
GJB1	NM_001097642.3	c.123G>C	p.Glu41Asp	missense_variant	2/2
GJB1	XM_011530907.3	c.123G>C	p.Glu41Asp	missense_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GJB1	ENST00000361726.7	c.123G>C	p.Glu41Asp	missense_variant	2/2	1	NM_000166.6	P1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: no assertion criteria provided

Submissions by phenotype

Charcot-Marie-Tooth disease Uncertain:1

Uncertain significance, no assertion criteria provided

literature only

Inherited Neuropathy Consortium

-

- -

Charcot-Marie-Tooth disease X-linked dominant 1 Other:1

not provided, no classification provided

literature only

GeneReviews

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.67
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.50
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D;D;D;D;D;.;D
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.84	.;.;.;.;T;D;D
M_CAP	Pathogenic	0.84	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.3	M;M;M;M;.;.;M
MutationTaster	Benign	1.0	A;A;A
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-2.9	D;.;D;.;D;.;D
REVEL	Pathogenic	0.86
Sift	Uncertain	0.0080	D;.;D;.;D;.;D
Sift4G	Uncertain	0.020	D;.;D;.;T;.;D
Polyphen		1.0	D;D;D;D;.;.;D
Vest4		0.82
MutPred		0.94		Gain of sheet (P = 0.1539);Gain of sheet (P = 0.1539);Gain of sheet (P = 0.1539);Gain of sheet (P = 0.1539);Gain of sheet (P = 0.1539);Gain of sheet (P = 0.1539);Gain of sheet (P = 0.1539);
MVP		1.0
MPC		1.8
ClinPred		0.97	D
GERP RS		3.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.81
gMVP		0.99

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs116840816; hg19: chrX-70443680;